Cell Biology Overview

Questions and Answers

What is the Cell Theory?

All living things are composed of cells.

Cells are the basic unit of structure and functions in living things.

All cells come from pre-existing cells.

All of the above. (correct)

What are organelles?

Parts in a cell that have different jobs.

What are prokaryotic cells?

Cells that lack a nucleus and most organelles.

What are eukaryotic cells?

Cells that have a nucleus and many organelles. Signup and view all the answers

What are the key differences between plant and animal cells?

Animal cells have a centriole. Signup and view all the answers

What is the function of the cell wall?

Supports and protects the cell. Signup and view all the answers

What does the cell membrane do?

Supports the cell and controls movement of materials. Signup and view all the answers

What is the role of the nucleus?

Controls cell activities and contains heredity material. Signup and view all the answers

What does the nuclear membrane control?

The movement of materials in and out of the nucleus. Signup and view all the answers

What is the function of the cytoplasm?

Supports and protects cell organelles. Signup and view all the answers

What does the E.R. do?

Carries materials through the cell. Signup and view all the answers

What is the function of ribosomes?

Make proteins. Signup and view all the answers

What does the Golgi apparatus do?

Modifies, stores, and routes proteins/products. Signup and view all the answers

What are lysosomes?

Sacs that digest products and destroy harmful bacteria. Signup and view all the answers

What is the cytoskeleton?

A network of fibers that helps maintain cell shape. Signup and view all the answers

What is the function of mitochondria?

Release energy from sugars and form ATP. Signup and view all the answers

What are phospholipids?

Lipids in the cell membrane with hydrophilic heads and hydrophobic tails. Signup and view all the answers

What are the two types of transport in cells?

Active transport Signup and view all the answers

What is diffusion?

Movement of particles from higher to lower concentration. Signup and view all the answers

What is facilitated diffusion?

Movement of substances from high to low concentration using proteins. Signup and view all the answers

What is osmosis?

The movement of water across a selectively permeable membrane. Signup and view all the answers

What characterizes an isotonic solution?

Equal distribution of solutes. Signup and view all the answers

What characterizes a hypertonic solution?

More solute causing cells to shrink. Signup and view all the answers

What characterizes a hypotonic solution?

More solvent causing cells to expand. Signup and view all the answers

The four functions of membrane proteins include __________.

enzymes, cell recognition, cell signaling, and transporting materials. Signup and view all the answers

What is active transport?

Movement of molecules or ions using energy. Signup and view all the answers

What is exocytosis?

The process of materials exiting the cell via vesicles. Signup and view all the answers

What is endocytosis?

The process of materials entering the cell via vesicles. Signup and view all the answers

What are the two types of endocytosis?

Both A and B Signup and view all the answers

Study Notes

Cell Theory

All living organisms are composed of cells; these are the fundamental units of structure and function.
Cells arise from pre-existing cells, ensuring continuity in living systems.

Cell Timeline

Electron beam microscopes, including SEM (Scanning Electron Microscope) and TEM (Transmission Electron Microscope), revolutionized cell observation.

Organelles

Organelles perform various functions within the cell, each playing a distinct role in cellular operation.

Prokaryotic Cells

Characterized by the absence of a nucleus and most organelles.
These are the earliest forms of life on Earth.

Eukaryotic Cells

Contain a nucleus as well as multiple organelles, supporting more complex functions.

Plant vs. Animal Cells

Animal cells possess centrioles and flagella.
Plant cells contain chloroplasts, a cell wall, and a central vacuole, contributing to their unique functions.

Cell Wall

Provides structural support and protection for the cell.
Facilitates water diffusion in and out of the cell.

Cell Membrane

Protects the cell by separating internal and external environments.
Regulates material movement into and out of the cell.

Nucleus

Acts as the control center for cell activities.
Houses genetic material necessary for heredity.

Nuclear Membrane

Manages the exchange of materials between the nucleus and the cytoplasm.

Cytoplasm

Supports and safeguards cell organelles, providing a medium for biochemical processes.

Endoplasmic Reticulum (E.R.)

Transports materials within the cell.
Rough E.R. is studded with ribosomes, while Smooth E.R. lacks them.

Ribosomes

Responsible for protein synthesis, fundamental for cell functions.

Golgi Apparatus

Modifies, stores, and directs proteins and products to their respective destinations.

Lysosomes

Digestive sacs containing enzymes that break down waste and harmful bacteria.

Cytoskeleton

A framework of fibers that helps maintain the cell's shape and organization.

Mitochondria

Powerhouses of the cell that convert sugar into energy (ATP).

Phospholipids

Key components of the cell membrane, featuring hydrophilic heads and hydrophobic tails.

Types of Transport

Passive Transport: Occurs without energy expenditure.
Active Transport: Requires energy to move substances against their concentration gradient.

Diffusion

Process of particles moving from areas of higher to lower concentration until equilibrium is achieved; occurs without energy.

Facilitated Diffusion

A form of passive transport that uses membrane proteins to assist in the movement of specific substances from high to low concentration.

Osmosis

A specific type of passive transport focusing on the movement of water through a selectively permeable membrane.

Isotonic Solution

Achieves equal distribution of solute and solvent across a membrane.

Hypertonic Solution

Contains a higher concentration of solute, leading to cell shrinkage due to water loss.

Hypotonic Solution

Has a lower concentration of solute, causing cells to swell as water enters.

Functions of Membrane Proteins

Enzymatic activity: Accelerate biochemical reactions.
Cell recognition: Facilitate identification between cells.
Signal transduction: Allow communication and message transfer within cells.
Transport: Assist the movement of materials across the membrane.

Active Transport

Utilizes energy for the movement of molecules from lower to higher concentration; may involve protein pumps or large vesicles.

Exocytosis

The process of expelling materials from a cell using vesicles.

Endocytosis

The intake of materials into a cell, also via vesicles.

Types of Endocytosis

Phagocytosis: Engulfing entire cells or large particles.
Pinocytosis: Uptake of external fluid and solutes.

Studying That Suits You

Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

Description

Explore the fundamental concepts of cell theory, organelles, and the distinction between prokaryotic and eukaryotic cells. This quiz covers the differences between plant and animal cells as well as advancements in cell observation technology. Test your knowledge on how cellular structures underpin the functionality of all living organisms.